4F2hc stabilizes GLUT1 protein and increases glucose transport activity
4F2hc stabilizes GLUT1 protein and increases glucose transport activity
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DOI：
10.1152/ajpcell.00416.2010
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发表时间：
2011-05-01
影响因子：
5.5
通讯作者：
Asano, Tomoichiro
中科院分区：
文献类型：
--
作者：
Ohno, Haruya;Nakatsu, Yusuke;Asano, Tomoichiro
Ohno H，中津Y，Sakoda H，Kushiyama A，Ono H，Fujishiro M，Otani Y，Okubo H，Yoneda M，福福岛T，Tsuchiya Y，Kamata H，Nishimura F，Kurihara H，Katagiri H，Oka Y，Asano T. 4F 2 hc稳定GLUT 1蛋白并增加葡萄糖转运活性。美国生理学杂志细胞生理学300：C1047-C1054，2011年。首次发表于2011年1月26日; doi：10.1152/ajpcell.00416.2010。葡萄糖转运蛋白1（GLUT 1）广泛分布于各种组织中，有助于胰岛素非依赖性基础葡萄糖摄取。利用分裂泛素膜酵母双杂交系统，我们新确定4F 2重链（4F 2 hc）作为与GLUT 1相互作用的膜蛋白。虽然据报道4F 2 hc在氨基酸转运蛋白（如LAT 1和LAT 2）之间形成异二聚体复合物，并调节氨基酸摄取，但我们研究了4F 2 hc对GLUT 1表达和相关葡萄糖摄取的影响。首先，FLAG标记的4F 2 hc和血凝素标记的GLUT 1在人胚肾293细胞中过表达，并通过免疫共沉淀证实了它们的关联。绿色荧光蛋白标记的4 F2 hc和DsRed标记的GLUT 1在质膜上显示出显着但不完整的共定位。此外，使用小鼠脑组织和HeLa细胞证明了GLUT 1和4F 2 hc之间的内源性关联。有趣的是，4F 2 hc的过表达增加了HeLa和HepG 2细胞中GLUT 1蛋白的量，并增加了葡萄糖摄取。相比之下，小干扰RNA（siRNA）介导的4F 2 hc基因抑制显着减少GLUT 1蛋白在两种细胞类型，减少葡萄糖摄取。虽然GLUT 1 mRNA水平不受4F 2 hc过表达或基因沉默的影响，但添加放线菌酮后的GLUT 1降解受到4F 2 hc过表达的显著抑制，并受到4F 2 hc siRNA处理的增加。综上所述，这些观察结果表明，4F 2 hc可能参与GLUT 1的稳定，并有助于调节不仅氨基酸，而且葡萄糖代谢。
Ohno H, Nakatsu Y, Sakoda H, Kushiyama A, Ono H, Fujishiro M, Otani Y, Okubo H, Yoneda M, Fukushima T, Tsuchiya Y, Kamata H, Nishimura F, Kurihara H, Katagiri H, Oka Y, Asano T. 4F2hc stabilizes GLUT1 protein and increases glucose transport activity. Am J Physiol Cell Physiol 300: C1047-C1054, 2011. First published January 26, 2011; doi:10.1152/ajpcell.00416.2010.-Glucose transporter 1 (GLUT1) is widely distributed throughout various tissues and contributes to insulin-independent basal glucose uptake. Using a split-ubiquitin membrane yeast two-hybrid system, we newly identified 4F2 heavy chain (4F2hc) as a membrane protein interacting with GLUT1. Though 4F2hc reportedly forms heterodimeric complexes between amino acid transporters, such as LAT1 and LAT2, and regulates amino acid uptake, we investigated the effects of 4F2hc on GLUT1 expression and the associated glucose uptake. First, FLAG-tagged 4F2hc and hemagglutinin-tagged GLUT1 were overexpressed in human embryonic kidney 293 cells and their association was confirmed by coimmunoprecipitation. The green fluorescent protein-tagged 4F2hc and DsRed-tagged GLUT1 showed significant, but incomplete, colocalization at the plasma membrane. In addition, an endogenous association between GLUT1 and 4F2hc was demonstrated using mouse brain tissue and HeLa cells. Interestingly, overexpression of 4F2hc increased the amount of GLUT1 protein in HeLa and HepG2 cells with increased glucose uptake. In contrast, small interfering RNA (siRNA)-mediated 4F2hc gene suppression markedly reduced GLUT1 protein in both cell types, with reduced glucose uptake. While GLUT1 mRNA levels were not affected by overexpression or gene silencing of 4F2hc, GLUT1 degradation after the addition of cycloheximide was significantly suppressed by 4F2hc overexpression and increased by 4F2hc siRNA treatment. Taken together, these observations indicate that 4F2hc is likely to be involved in GLUT1 stabilization and to contribute to the regulation of not only amino acid but also glucose metabolism.